Hey folks, new here. Hope I'm posting in the right spot.
I have a Peavey Special 212 combo I'm working on, 90s Transtube series. Very similar to the Peavey Supreme transtube head I believe. I'll try to post the schematic in here. For reference, I do have experience working on both tube and solid state amps already.
I got this amp in working condition, though it needed some repairs (slight buzzing, sounded like filter cap leak, and scratchy pots along with a couple damaged jacks). Also, not sure if it was my doing when I was testing the amp after replacing the filter caps, but one or 2 of the output transistors shorted.
The power section is setting off my light bulb limiter. (Red wire from the transformer). The preamp section does not set it off with the power section unplugged, BUT channel switching isn't working at the moment (maybe the power section needs to be plugged in?)
So, I've replaced all of the big electrolytics (triple checked orientations), replaced all pots, replaced output transistors with onsemi equivalents (15003g and 15004g), replaced driver transistors that sit before those, and all power section transistors tested good. I've also replaced the diodes from CR53 down to CR71 (check schematic). Nothing is fried resistor wise. I checked voltages at key points and they're all there, but when I plug the transformer into the power section, the LEDs fade out and everything seems to get dragged down. Running out of ideas, and I'm asking for some help or suggestions to get this thing going again.
Link to the schematic: SPECIAL 212 SCHEMATICS
I have a Peavey Special 212 combo I'm working on, 90s Transtube series. Very similar to the Peavey Supreme transtube head I believe. I'll try to post the schematic in here. For reference, I do have experience working on both tube and solid state amps already.
I got this amp in working condition, though it needed some repairs (slight buzzing, sounded like filter cap leak, and scratchy pots along with a couple damaged jacks). Also, not sure if it was my doing when I was testing the amp after replacing the filter caps, but one or 2 of the output transistors shorted.
The power section is setting off my light bulb limiter. (Red wire from the transformer). The preamp section does not set it off with the power section unplugged, BUT channel switching isn't working at the moment (maybe the power section needs to be plugged in?)
So, I've replaced all of the big electrolytics (triple checked orientations), replaced all pots, replaced output transistors with onsemi equivalents (15003g and 15004g), replaced driver transistors that sit before those, and all power section transistors tested good. I've also replaced the diodes from CR53 down to CR71 (check schematic). Nothing is fried resistor wise. I checked voltages at key points and they're all there, but when I plug the transformer into the power section, the LEDs fade out and everything seems to get dragged down. Running out of ideas, and I'm asking for some help or suggestions to get this thing going again.
Link to the schematic: SPECIAL 212 SCHEMATICS